Planning for Electric Buses
Planning for the adoption of electric buses and the installation of charging infrastructure will likely be driven by the transit agency, in coordination with the many partners previously discussed. Many existing resources provide guidance on incorporating BEBs into service, such as the Transit Cooperative Research Program’s (TCRP) Guidebook for Deploying Zero-Emission Transit Buses, NREL’s Electrifying Transit: A Guidebook for Implementing Battery Electric Buses, and DOE’s Flipping the Switch on Electric School Buses series. These resources provide step-by-step considerations through all the phases of planning, purchase, and deployment of buses and infrastructure, operations and maintenance, and performance monitoring.
Usage of BEBs requires the purchase not only of the vehicles, but also the upfront costs of purchasing and installing the charging infrastructure, which may require utility upgrades and/or maintenance facility modifications. The charging infrastructure for BEBs will need to be carefully considered as it does not scale linearly with fleet size, meaning that there will be incremental costs and space requirements as fleet size increases. The operation of BEBs will require hiring new staff and/or training existing staff in the operation and maintenance of BEBs to ensure the efficient use and maintenance of the vehicles. Due to these complexities, it is important that transit agencies plan effectively for the purchase of BEBs and charging infrastructure to ensure a system that best fits their needs and constraints.
In addition to the planning required to incorporate BEBs into a fleet, the transit agency will need additional planning to guide the operation of BEBs. Each BEB purchased will have an expected range, but weather (with a lower range in cold and hot temperatures), driving behavior of the operators, topography, and ridership load will impact that range. These external factors mean that transit agencies will experience variability in range projections; however, tracking of range over time can help to predict this variability and mitigate any impacts to service. If electricity rates are high, this will have a significant impact on operational costs. To minimize this uncertainty, transit agencies can discuss rate structures with their utility company to identify opportunities to lessen costs.
Transit agencies will need to consider their objectives, resources, and constraints prior to purchasing and deploying buses and charging infrastructure. Data collected through fleet and route assessments can help agencies understand their transportation and energy needs. For example, TCRP recommends designing smaller deployment projects to test implementation and then planning iteratively, with internal and external stakeholder engagement, to build out the BEB fleet. Each phase of deployment can be discussed with bus manufacturers to help plan for the needs of each acquisition. The needs assessment phase should consider the various factors that will influence decisions in bus and charging infrastructure purchasing, including route structure and length (to understand energy requirements), bus schedules and demand, bus depot capacity, utility rate schedule and costs, and local climate and topography. Tools that may assist with this needs assessment include the FTA Transit Greenhouse Gas Emissions Estimator, which estimates annual GHG emissions of transit projects based on the construction, operation, and/or maintenance phases of transit facilities and vehicles, and their Transit Bus Electrification Tool, which estimates the partial lifecycle GHG emission savings associated with replacing standard bus fleets with low-emission or zero-emission transit buses. DOE also has a GHG and cost estimator for transit buses, the Alternative Fuel Life-Cycle Environmental and Economic Transportation (AFLEET) Tool.
